Rework DV aggregation selection proofs (#15156)

* Reword DV selection proofs

* Add changelog

* Expect 1 call to DomainData in DV update duties test

---------

Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

validator/client/aggregate.go

@@ -45,16 +45,7 @@ func (v *validator) SubmitAggregateAndProof(ctx context.Context, slot primitives
 	}
 
 	var slotSig []byte
-	if v.distributed {
-		slotSig, err = v.attSelection(attSelectionKey{slot: slot, index: duty.ValidatorIndex})
-		if err != nil {
-			log.WithError(err).Error("Could not find aggregated selection proof")
-			if v.emitAccountMetrics {
-				ValidatorAggFailVec.WithLabelValues(fmtKey).Inc()
-			}
-			return
-		}
-	} else {
+	if !v.distributed {
 		// Avoid sending beacon node duplicated aggregation requests.
 		k := validatorSubnetSubscriptionKey(slot, duty.CommitteeIndex)
 		v.aggregatedSlotCommitteeIDCacheLock.Lock()
@@ -80,6 +71,21 @@ func (v *validator) SubmitAggregateAndProof(ctx context.Context, slot primitives
 	// https://github.com/ethereum/consensus-specs/blob/v0.9.3/specs/validator/0_beacon-chain-validator.md#broadcast-aggregate
 	v.waitToSlotTwoThirds(ctx, slot)
 
+	// In a DV setup, selection proofs need to be agreed upon by the DV.
+	// Checking for selection proofs at slot 0 of the epoch will result in an error, as the call to the DV executes slower than the start of this function.
+	// Checking for selection proofs after 2/3 of slot in a DV setup is much faster than non-DV as it's quickly fetched from memory,
+	// hence it does not slow down the aggregation as a non-DV would.
+	if v.distributed {
+		slotSig, err = v.attSelection(attSelectionKey{slot: slot, index: duty.ValidatorIndex})
+		if err != nil {
+			log.WithError(err).Error("Could not find aggregated selection proof")
+			if v.emitAccountMetrics {
+				ValidatorAggFailVec.WithLabelValues(fmtKey).Inc()
+			}
+			return
+		}
+	}
+
 	postElectra := slots.ToEpoch(slot) >= params.BeaconConfig().ElectraForkEpoch
 
 	aggSelectionRequest := &ethpb.AggregateSelectionRequest{

validator/client/validator.go

@@ -830,6 +830,7 @@ func (v *validator) isAggregator(
 		err     error
 	)
 	if v.distributed {
+		// This call is blocking. It is awaitng for selection proof response from DV to be written in memory.
 		slotSig, err = v.attSelection(attSelectionKey{slot: slot, index: validatorIndex})
 		if err != nil {
 			return false, err
@@ -1493,8 +1494,12 @@ func (v *validator) aggregatedSelectionProofs(ctx context.Context, duties *ethpb
 	ctx, span := trace.StartSpan(ctx, "validator.aggregatedSelectionProofs")
 	defer span.End()
 
+	// Lock the selection proofs until we receive response from DV.
+	v.attSelectionLock.Lock()
+	defer v.attSelectionLock.Unlock()
+
 	// Create new instance of attestation selections map.
-	v.newAttSelections()
+	v.attSelections = make(map[attSelectionKey]iface.BeaconCommitteeSelection)
 
 	var req []iface.BeaconCommitteeSelection
 	for _, duty := range duties.CurrentEpochDuties {
@@ -1515,52 +1520,20 @@ func (v *validator) aggregatedSelectionProofs(ctx context.Context, duties *ethpb
 		})
 	}
 
-	for _, duty := range duties.NextEpochDuties {
-		if duty.Status != ethpb.ValidatorStatus_ACTIVE && duty.Status != ethpb.ValidatorStatus_EXITING {
-			continue
-		}
-
-		pk := bytesutil.ToBytes48(duty.PublicKey)
-		slotSig, err := v.signSlotWithSelectionProof(ctx, pk, duty.AttesterSlot)
-		if err != nil {
-			return err
-		}
-
-		req = append(req, iface.BeaconCommitteeSelection{
-			SelectionProof: slotSig,
-			Slot:           duty.AttesterSlot,
-			ValidatorIndex: duty.ValidatorIndex,
-		})
-	}
-
 	resp, err := v.validatorClient.AggregatedSelections(ctx, req)
 	if err != nil {
 		return err
 	}
 
 	// Store aggregated selection proofs in state.
-	v.addAttSelections(resp)
-
-	return nil
-}
-
-func (v *validator) addAttSelections(selections []iface.BeaconCommitteeSelection) {
-	v.attSelectionLock.Lock()
-	defer v.attSelectionLock.Unlock()
-
-	for _, s := range selections {
+	for _, s := range resp {
 		v.attSelections[attSelectionKey{
 			slot:  s.Slot,
 			index: s.ValidatorIndex,
 		}] = s
 	}
-}
 
-func (v *validator) newAttSelections() {
-	v.attSelectionLock.Lock()
-	defer v.attSelectionLock.Unlock()
-
-	v.attSelections = make(map[attSelectionKey]iface.BeaconCommitteeSelection)
+	return nil
 }
 
 func (v *validator) attSelection(key attSelectionKey) ([]byte, error) {

validator/client/validator_test.go

@@ -595,7 +595,7 @@ func TestUpdateDuties_Distributed(t *testing.T) {
 	).Return(
 		&ethpb.DomainResponse{SignatureDomain: sigDomain},
 		nil, /*err*/
-	).Times(2)
+	)
 
 	client.EXPECT().AggregatedSelections(
 		gomock.Any(),